Lithium - anything batteries last best when not used to full discharge.
Going below 20% capacity in the battery, impacts the life of the battery
(same in your phone, constantly running it "Flat" does the internal battery

no favours at all.)

Chargers, it's not "Important" to use Proper chargers, it's "Vital".
Lead acid batteries are from the Steam era.
Modern Hi Capacity, Hi Discharge batteries are hugely powerful wee
beasties.
Not to be treated with the same practices as Lead Acid lumps.

Lithium Phosphate - LiFePo4 - Li4 batteries are less likely to misbehave
when charged badly.
LiPo - Lithium Ion, take badly to being dropped, shorted out, mischarged.
In use, liFePo4 batteries are slightly more idiot proof.
LiPo Batteries are lighter and have higher energy density.

You can Charge LiFePo4 in situ in the glider.
It is unwise to charge LiPo in the glider.

You _must_ have over discharge protection in place on a LiPo battery, it is

wise to have over dishcarge protection on a LiFePo4 battery.